Yasushi Yamaguchi, originally the main artist and zone designer for Sega's Sonic Team, designed Tails for an internal competition for a sidekick to the speedy hedgehog. The character was meant to hold a "deep admiration for Sonic."[3] Tails was originally intended to be a tanuki, a strikingly raccoon-like canid native to east Asia, and extremely popular in Japanese folklore. The designers decided to change him to a fox, however, to avoid possible comparisons with another popular game character.[4]
His entry won, but Sonic Team decided to change his character's name from "Miles" to "Tails."

Yamaguchi ended up with a compromise. He sneaked the name "Miles" in as his legal name; "Tails" would be his nickname, ending up with the full name of Miles "Tails" Prower which is a pun of the phrase "miles per hour".

The character debuted as Sonic's tag along partner in the franchise's second game, and has remained an important player since. However the character's uniqueness wasn't established until Sonic the Hedgehog 3 when players were given the power to control his flying.[5]

Tails was redesigned (along with all of the other Sonic characters) by Yuji Uekawa for Sonic Adventure. His fur changed color to a slightly orange shade of yellow, and he gained visible blue irises.

Tails was first seen in Sonic 2 for the Sega Master System. He was first made playable in the Genesis version of Sonic the Hedgehog 2, playing the part of Sonic's sidekick. He was a playable character from the second controller and could be chosen as player one for the main game. Sonic Chaos (1993), on the Game Gear/Master System was the second game where the player could control Tails, and the first time the player could control his flight.

Tails made his third major appearance in 1994 when Sonic 3 was released, this time acquiring the ability to pick up Sonic and use his tails to fly him to other areas, rotating his tails like a helicopter. He also gained the ability to swim under water, something Sonic has never been able to do.

In later games, Tails has had roles that require unique modes of play. For example, in Sonic Adventure, Tails is one of the six playable characters[7] and his gameplay is standard platforming stages, but the goal of each stage is to get to the Chaos Emerald before Sonic, or to the missile dud in the final race against Dr. Eggman.

In the sequel to Sonic Adventure, Sonic Adventure 2, he is featured in third-person shooting segments, seated in his "Cyclone" mech.[8] This third-person shooter style of play, along with Dr. Eggman's shooting levels in the same game, were very similar to the E-102 Gamma levels of Sonic Adventure.

Tails has appeared either as a playable character or in a supporting role in almost all later Sonic titles. He still often resumes his role flying other characters around, such as in Sonic Heroes, where Tails appears on Team Sonic as their flight-type character, being capable of carrying both Sonic and Knuckles.[9]

In Adventures of Sonic the Hedgehog, he is supposedly significantly younger than in the games; he is "only 4 and a half," while in the games, he is eight. As with the game canon, his real name is Miles Prower. However, his fur is brown in the cartoon as opposed to orange in the games. Sonic's relationship with Tails is much closer than in the games; here, they are portrayed as surrogate brothers, with Sonic being more-or-less Tails' legal guardian: on the 16th episode, "Tails' New Home", the origin how he and Sonic first meet was seen in Sonic's flashback while he was thinking about the times with him; around that time, Tails was an 1-year-old baby. Tails is apparently an orphan, and was raised by birds, thus strangely explaining his ability to fly.

While Tails is indeed useful to Sonic in many situations, he can be a hindrance. Because he is very young and cannot defend himself, he is incredibly susceptible to being kidnapped by Robotnik and used as bait for Sonic. Sonic appears to know of this flaw and does his best to protect him, but his protection methods are often the reason why Tails gets kidnapped in the first place. Like Sonic, his favorite food is chili dogs, but apparently Tails likes extra cheese on his (in the anime and games, his favorite food is mint candy).[11] He also hates his real name and doesn't want anyone to know about it, a fact that Sonic occasionally exploits to blackmail him out of danger.

Tails is the son of Rosemary and Amadeus Prower; Sonic was present at the time of Tails' birth, and the two immediately bonded. After being separated from them by Dr. Robotnik, he grows up in Knothole Village with Sonic the Hedgehog and the other Freedom Fighters. He joins the Freedom Fighters, though he is unable to work in some of the more dangerous missions; when he does work in them, he mostly serves to pilot the group's escape vehicle and stays on board during that time. He eventually leaves on an adventure where he learns from Athair that he is the "Chosen One," a great hero that will bring about "The Great Harmony." He eventually becomes the target of Mammoth Mogul, and the two do battle on various occasions. After Robotnik is overthrown, Tails begins living with Sonic and his parents.

Tails later completes part of the Great Harmony by sealing away the Chaos Emeralds in a special dimension after being captured by A.D.A.M.. Sonic begins dating Fiona Fox, Tails's crush, which causes a rift between them. When the two return Tails's parents to Mobius, the rift widens when the two get involved in a political schism started by Amadeus, Tails supporting his father and Sonic remaining loyal to the House of Acorn. Eventually, after an argument, the two reconcile after Sonic apologizes and explains that he had dated Fiona in the hopes that it would help Tails get over his feelings for her. He later helps in the fight against his fellow Freedom Fighters anti counterparts once again. He also helped in the recent battle against Dr. Eggman, which results in Eggman descending into complete insanity.

In the possible future of Mobius: 25 Years Later, it is revealed that Sonic and Tails had a falling out three years before the sub-series begins, and are no longer on speaking terms. In this timeline, Tails has married Mina Mongoose and had two children (a son and a daughter who resemble himself and Mina, respectively), and is currently living on the continent of Downunda (the Mobius equivalent to Australia). When Sonic travels back in time to avert the possible end of all existence and alters history so that Shadow rules the planet in a ruthless, despotic manner, Tails senses that something is wrong and goes to lengths to keep his memories and those of his family intact, and later, along with Knuckles' daughter, Lara-Su, finds Sonic living on the streets of Portal. Sonic, wanting to repair their friendship if he couldn't undo the damage he had already done, apologizes for letting things get so bad between them, and Tails forgives him. He later assists Sonic in overthrowing Shadow.

Tails also appears in the British Sonic the Comic, published by Fleetway.[12] Here, he first met Sonic when the latter saved him from drowning in a swamp. In this series Tails was older than his other incarnations, and was frequently the butt of many of Sonic's cruel jokes, most often being called "pixel brain". He is initially portrayed as a bit of a push-over, who constantly allows Sonic to insult him, gets flustered in dangerous situations, and had a significant inferiority complex. As time went on, Tails became more competent and heroic. On occasion he would return to his home land 'The Nameless Zone' where he would get a suit of silver armour and a short sword. When the comic began adapting Sonic Adventure, Tails' eyes remained brown while Knuckles and Sonic had their eyes changed to match their in-game counterparts.

Throughout most of the anime series Sonic X, Tails mirrors his game role in various stories and game adaptations, though he often plays a smaller role in the series due to the presence of Chris Thorndyke. He quickly befriends fellow inventor Chuck Thorndyke, who built the X-Tornado jet with him.

In the third season of Sonic X, Tails is the captain of the Blue Typhoon, and over the series develops leadership. Tails falls in love with Cosmo, a plant-like female alien introduced during this season. He broke down emotionally at the conclusion when Cosmo asked him to sacrifice her to defeat the Metarex, but kept one of the seeds she released which sprouted.

The character of Tails is portrayed as a very sweet-natured[13] and humble fox;[14] who, before he met Sonic, used to be picked on because of his twin tails.[1] As a long time friend,[13] he admires Sonic[15] and dreams of being just like him.[16] Though he lacks courage,[1] he wants to prove he can be counted on[17]. He loves mint candy,[18] tinkering with machines, and flying mechas.[1] Tails has a fear of thunder[18] and a tendency to rambleTemplate:Fact.

Tails has been described as a mechanical prodigy who rivals Dr. Robotnik, however he has yet to realize his full potential[15]. Additionally, by spinning his two tails like a helicopter rotor, he has the unique ability to push himself through the air[13] to catch up with Sonic. However, when he takes to flight, he tires quickly.[13] Tails is also able to swim.[19]

Tails was awarded "Best New Character" in Electronic Gaming Monthly's 1992 video game awards, stating "not only is he as cute as Sonic, but he actually serves a major purpose in the game."[20] IGN said Tails was "welcomed by fans" but was also a "harbinger of future concerns over the direction of the series" as the series added too many characters.[21] IGN's Colin Moriarty singled out the introduction of both Tails and Knuckles as when the series became "iffy" and listed them and all other characters in the series, sans Sonic and Robotnik, as being 2nd most in need to "die" on his top 10 list.[22]